The 27-year-old DNCE frontman and 20-year-old Game of Thrones star were spotted kissing at a Kings of Leon concert prior to the 2016 MTV Europe Music Awards on Saturday.
"Joe and Sophie arrived together before the show started," a source told Us Weekly. "He had his arm around her as they walked in, and then he was holding her before the show. Joe and Sophie kissed a few times and were talking and drinking soda."
"When the lights went down and Kings of Leon started they were dancing together and singing along. Joe would kiss her cheek as they danced next to each other," the insider added.
Jonas and Turner were seated next to the singer's DNCE bandmates JinJoo Lee and Cole Whittle. A source told People the pair appeared to be on a date and seemed surprisingly "comfortable" around each other.
"They were really close together," the insider said. "The two or three times I was watching they were kissing. She was all smiley and he looked really sweet."
Jonas and DNCE later performed their singles "Body Moves" and "Cake by the Ocean" at the MTV EMAs, where they won Best Push Act. The singer tweeted a photo from the ceremony, writing, "#TEAMDNCE ALL YOU!"
"I've never dated anyone who I didn't know before or who's in the industry," the actress said in the July issue of InStyle U.K. "I think that's quite a conscious decision because the lifestyles wouldn't work. This profession is so different to any other; the going away for long amounts of time -- I think it would just be really difficult."